I have a house with multiple music zones. I don't necessarily want them all on at the same time. So whether I go with several small amps, or one with trigger inputs per zone- I'd like to have a single smart device that is capable of sending a small voltage/amperage via several outputs. These output…

Closing the loop on this one. Ultimately, I gave up on the more integrated home built direction. Sonos has an amp that I've gotten a few of, and does most of what I need. The only thing I'm really missing from it is being able to use my home theater as the audio source - which for my actual use case…